Means for actuating enclosed electric switches



Feb. 4, 1936. ATORNBL 2,029,599

MEANS FOR ACTUATING ENCLOSED ELECTRIC SWITCHES Filed Oct. 22, 1934 r of the switch in or its removal from the box. One

Patented Feb. 4, 1936 MEANS FOR ACTUATING ENCLOSED ELECTRIC SWITCHES Nils A. Tornblom, Chicago, Ill., assignor to Appleton Electric Company, a corporation of Illinois Application October 22, 1934, Serial No. 749,421

3 Claims.

The present invention relates to means for operating electric switches .enclosed in a protective housing and has for its object to produce an improved means for this purpose.

One of the reasons for enclosing a switch is to prevent arcing thereof from causing ignition of inflammable or explosive gases in or forming the surrounding atmosphere and, therefore, the opening and closing of the switch must be effected from without the protective housing. One of the objects of the present invention is to produce a simple and novel joint between a wall of a housing and a rotatable or oscillatory actuating member passing through the same, whereby the joint will be effective to prevent leaks of a charactor that might cause an inflammable surrounding atmosphere to be ignited. More specifically considered, viewing the invention in this aspect, the object of the invention is to produce what may be termed an explosion proof joint without the use of packing or stufiing boxes and without making the housing wall exceedingly thick at the point where the actuating member passes through the same.

One of the commonest forms of switches is that in which there is a pivoted switch arm for opening and closing the same. Viewed in one of its aspects, the present invention may be said to have for one of its objects to produce a simple and novel actuating means such that, although the actuating force is always applied at right angles to the switch arm, no sliding or idling contact is required between the actuating means and the switch arm or between parts of the actuating means.

Viewed in another of its aspects, the present invention may be said to have for its object to produce a simple and novel means for readily adjusting the connection between the switch arm and the actuator or between any swinging arm and a jaw-like part engaged therewith.

When a switch having its arm rising from the top thereof is housed in a box open or adapted to be opened at the top, the actuator for the arm must, of course, overlie the switch and would therefore ordinarily interfere with the insertion of the objects of the present invention is to produce a simple and novel actuator for use in a situation of this kind, whereby, without dismantling the actuator or disconnecting it from the box or housing, it may be quickly and easily adjusted to leave the space above the switch clear and unobstructed by any part of the actuator.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is a top plan view of a housed switch containinga preferred embodiment of my invention, the cover of the housing being omitted; Fig. 2 is a section on line 22 of Fig. 1, the switch being shown in elevation; Fig. 3 is a view showing fragments of the switch arm and of the actuator, looking in the direction of the arrow 3 in Fig. 2; and Fig. 4 is a side view of the rocker arm on the inner end of the actuating shaft, detached'fromthe shaft, together with a fragment of the member that is hinged thereto for driving the switch arm.

In the drawing I have illustrated only a single device or apparatus embodying in a preferred manner all of the various features of my invention, some of which features may, however, be employed independently of the others; and, for

the sake of brevity, the detailed description will be confined to this particular device or apparatus. Referring to the drawing, 5 represents any usual or suitable switch, from the top of which projects a switch arm 6 pivoted to swing about a horizontal axis indicated by line I in Fig. 2, and which corresponds with line 2-2 in Fig. l, in plan view. The switch is fixed in a .box or housing member 8 which is open at the top. The upper part of the box or housing is shown as being cylindrical so that the closure may be a round cap or cover 4 adapted to be screwed on. The parts are so proportioned that there is ample room within the closed box or housing, above and at one side of the switch, for the actuating means which I shall now describe.

In order that the power may be most effectively applied to the switch arm and that the same may be driven back and forth without any rubbing action between the same and the actuator, I have provided an actuator in the form of a rocking device whose rocking axis is a coneach other and without producing any sliding or rubbing action that will cause wear. The arm II is long enough so that the upper end thereof terminates at about the same level as the top of the switch arm. Hinged to the upper end of the arm II, so as to swing about an axis lying in a plane at right angles to the common pivotal axis of the switch arm and the arm II, is an auxiliary arm I2 or driving member. The left hand end of the member I2, as viewed in Figs. 1 and 2, is divided, or forms a fork l2, and embraces the upper end of the arm II. A hinge pin ll extends through the part II and the corresponding part of the arm II to form the hinge connection. At the free end of the arm I2 is a wide jaw i5 into which the upper end of the switch arm 8 extends. A pair of aligned screws II, I, parallel with the hingle pin ll, extend through the two arms or sides of the jaw ii, the heads of the screws being on the inner ends and being rounded for contact with the front and rear edges or faces of the switch arm, respectively. Each screw has a long slot I! cut into the same through the free end, these slots extending diametrically across the screws. The little hubs l8, through which the screws l6 extend and which form parts of the jaw l5, are perforated for the reception of cotter pins I! or the like. After the screws have been adjusted the cotter pins ii are inserted, passing through the slots or cuts in the screws and holding the screws against turning. a

The reason for hinging the member I2 to the rocker arm II is to permit the member I2 to be swung up into the position shown in dotted lines in Fig. 2 at times when the switch is to be moved into or out of the box or housing, so as to form no obstruction in the path of the switch. When the member i2 is in its normal position of use, however, it should be held against movements of any kind relatively to the arm ll. Therefore, as best shown in Fig. 4, the arm I l is provided with a lug 20 on which the inner end of the arm or member l2 may rest when in its operative position. Also, rising from the upper end of the arm II is a lug or ear 2| having therein a hole 22. When the member I2 is swung down into its working position, the ear 2| projects above the same and a cotter pin 23 or other suitable device may be inserted in the hole or opening 22 in the ear and, by overlying the member l2, prevent the latter from being swung up out of operative relation to the switch arm.

Unless a stufling box of some kind be provided for the shaft 9, the bearing for this shaft must be made very long in order that the joint between the shaft and the housing be sufficiently tight to eliminate the danger of igniting combustible gases surrounding the housing when there is arcing at the switch. A long bearing, of course, means that the wall of the housing at the point where the rock shaft passes through the same must be made very thick. I avoid the necessity of providing an unduly thick housing wall, while compelling fluid or any thing else that might leak through the joint to follow a path much longer than the mere thickness of the wall, by providing the shaft with external screw threads 24 and screwing the shaft through the wall. Therefore, anything that attempts to enter or leave the housing past the rock shaft must follow a zigzag path which is, of course, much longer than would be the direct path where the shaft is a mere cylindrical member. By reason of the screw-threaded connection with the housing, the shaft moves endwise a slight distance whenever it is rocked. However, the angular movement of the rock shaft is small and therefore the endwise movement of the shaft is imperceptible.

While the extent of angular movement of the actuator will be limited by the movement permitted the switch arm, a keeper, such as indicated at 25, for the actuating handle or lever it may be fixed to the exterior of the housing to limit the angular movement of the handle or lever.

While I have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the definitions of my invention constituting the appended claims.

I claim:

1. In combination, a housing, a switch arranged within said housing and having a pivoted switch arm to operate the switch, of an actuating member extending through a wall of the housing and rotatable therein about a continuation of the pivotal axis of said switch arm, said actuating member being screw-threaded in said wall thereby to compel any fluid passing through the wall along said member to follow a path that is much longer than the thickness of. the wall, and means on the inner end of said member to interlock the same with said arm and compel the arm and the actuating member to swing in unison with each other whenever either moves angularly in either direction.

2. In combination, a housing having an opening, a switch in said housing adapted to be moved into and out of said housing through said opening, an actuator mounted on a stationary wall of the housing and including a member movable beside the switch'out of the path of the latter as it enters or leaves the housing, the switch having an arm for operating the same projecting from the side toward said opening, and a switch-arm engaging part mounted on said member for movements thereon from a position in which said part overlies the switch and engages said switch arm to a position in which it lies beside the path which the switch must travel in entering or leaving the housing.

3. In combination, a housing adapted to be opened at the top, a switch in the housing and adapted to be inserted or removed through the top of the housing, a switch arm on the upper side of the switch; and an actuator including a rocker comprising a shaft extending through a side wall of the housing and an arm on the inner end of the shaft, and a switch-arm engaging element mounted on the rocker arm for adjustment into either a position in which it overlies the switch or a position in which it stands at one side of the switch and leaves the switch a clear path for movements into or out of the housing.

NILS A. TORNBLOM. 

